Safety razor



H. M. CHANCE SAFETY RAZOR Filed July 20 1921 m T m V N 1 h, ha. 0AM

Patented June 3, 1924.

. U TED STATES PATENT. oFFiCE- nnnmr M. CHANCE, or PHILAJ'JELPEIA,rnnnsnvhma SAFETY RAZOR.

. Application filed July 20,

have invented certain new and useful Improvements in Safety Razors,whereof the following is a specification. a My invention relatesprimarily to safety razors that use a two-edged blade, that is a bladewith two. cutting edges, such, forexample, as the Gillette razor blade,but its; application is not limited to that particular kind of two-edgedblade, nor to the use of holders commonly used with such blades,as it isa plicable also to holders that donot curve or iiex the blade, totwo-edged blades that are not of the flexible type and to single-edgedblades. p

In flexible blade razors, flexing of the blade is used as a meansforadjusting the position of the cutting edges of the blade and theirangular direction, thus enabling the ,user, within certain limits, toadjust the cutting, edges to shave closely or not as may be desired.Owing to slight diflerences in such blades, all blades do, not flex orbend uniformly or symmetrically, and change in flexure of the. blade maycause the cutting edge to warp or curve in a simple or compound curve,insteadof bending to form the straight (or uniformly curved) linerequired for safe and efficient use. In addition to thisdiflicultyinherent to adjustment by flexing, ignorance, lack of skill orinattent'ion on-the part of the user in adjusting the blade for use,frequently are the cause of scraping of. the epidermis or actual cuttingofthe skin. For these reasons adjustments that do not depend for safetyupon the exercise of in.- telligence, skill or .care on the part of theuser are preferable to those that require skill insetting every time therazor is used.

Myinvention is intended to overcome, or

i to minimize the element of uncertainty and danger of damage in the useof safety razors. of the so-called'adjustable type and which depend uponfiexing the blade in varying degree to change the position of thecutting edge with reference to the guard. To justify the name. asafctyrazor should be a prac tirally safe instrument'when assembled for use inany possible position of the cutting edge and the guard.- To effectthis, it be struction of the 1921. Serial No. 486,148.

comes necessary to confine the range of the adjustment available to theuser, within preciseand definite limits.

I attain this object by flexing the-blade or by flexing a portion of theholder, or the guard,jin such manner as to change the relative position.of the guard with reference to the cutting edge adjacent thereto, thedegree of flexing, whether of the holder or of the blade, beingpositively limited by the conparts that co-act to produce the flexing. fr V Fig. I is an end and partly crosssectional View, showingmyinventionapplied tothe construction of a raz'orin which theholder isflexible andshowing the cutting edge of the blade and guard in aposition insuring the greatest safety, and Fig. 11 is another view ofthe samevdevice showing the holder flexed and-the cutting edge of'theblade and guard in a position'adapted for close shaving. These twoposit-ions being the extreme positions possible, any intermediateadjustment causes the cutting edge of the blade and of the blade withthe holder and clamp in approximately the position shown, which giveslittle, if any, exposure of the cutting edge of the blade, and Fig. IVshows the same device with the relative positions of cuttingedgeandguard changed to permit of use for close shaving, by flexingthe blade tothe greatest degree of flexingpossible, thus providing for practicallythe same range in relative positions ofthe cutting edges and guard asthat obtained by the device illustrated by Figs. I'andII,

In Figs. I and II, 1 is a flexible holder, 2, 3 are guards,showndiagrammatically as of the comb or toothed type, 4 isa doubleedgedrazor blade, 5 a clamp, 6 ascrew attached to clamp 5for clamping theparts together, and 7 1s a handlewith an internal .thread fittin thescrew'6-. 1 v

In Figs. I I and IV, 1' is a holder, 2', 3 are guards, 4' is adouble-edge flexible razor blade, is a clamp, 6' is a screw attachedthereto and 7 is a handle threaded toengage with the screw 6.

The drawings are made on a large scale and show the exposure-of thecutting edge, the clearances between the cutting edge and the guard, andthe differences in angular direction of the cutting edge "more or lessexaggerated in order to show clearly the vprinciple of construction. Inmost cases! the adjustment to be made betweenordinary at a creasing thedistance that the cutting edge I and close shaving conditions is verysmall, amounting to but a few hundredths or thousandths of an inch. Ifthe dimension :0 or y be relatively large, then 10 or 2 may be so smallthat the cutting edge to does not reach or intersect the line c-d, andyet may provide conditions that permit of satisfactory and evenrelatively close shaving if the razor be firmly pressed against theskin, be cause, owingto the distance being large,

the skin will curve inwards between the guard and the cutting edge a,thus bringmg the latter in contact with the skin. Un-

der these conditions the angles'bra-d, and b'a-d" will be much smallerthan .those shown diagrammatically by the drawings. It will of course beunderstood that in this,

as in all safety razors, .the safety of the,

razor is less when the razor is designed or adjusted for close shavingthan when the adjustment is for less close shaving.

In Fig. IV the cutting edge of the blade is shown projecting quite anappreciable distance beyond the line c d', a con dition that involvessome element of danger unless care be exercised by the user, and thisexaggerated condition shown may be avoid-' ed in practice, either byflattening the curve of the holder, lengthening the guards or deprojects beyond the holder 1'.

In carrying out my invention, I do not limit myself to the comb ortoothed type of guards shown by the drawings. It is ObVl".

ous that any suitable type of guard may be used, with or without teeth.If a bar be used as a guard, it may be separated from the cutting edgeand from the adjacent part of the holder by an open slot. Such barguards may be made with a smooth surface or may, be provided withcorrugations, projections or teeth. The advantage of thebar-type ofguard is that it does not clog, is easily cleaned and it facilitates theuse of an an lar sliding movement of the razor by which the cutting edgeis drawn diagonally across the hairs instead of squarely across them. Inusing atwo-edged blade, it may often be desirable to use different typesof guards for the two cutting edges. It will be understood that theresiliency of the holder, when a flexible holder is used, or of theblade, when a flexible blade is used, keeps a stress u on the screw 6which tends to hold or loc it in macaw place, thus keeping the razorfirmly clamped in the position in which it is set.

In the type of construction shown by Figs." I and II, the .end, 10, ofthe holder adjacent to the guard, is in contact'with the blade close toits cutting edge, firmly pressing. the blade against the clamp 5, thuskeeping the cutting edge from warping longi tudinally and holding itrigidly in place.

tion to each other such that-the cutting edge has its minimum degree ofexposure and its maximum degree of protection by the guard, and is nottherefore in the position best adapted for close shaving;

. 2. If the clamp be further tightened, the position of the cutting edgeand guard with relation to each other is changed in such manner as toincrease the exposure of the cutting edge, and decrease the degree ofpm:

I tection of the. guard, thus bringing the cutting edge. into a positionbetter adapted for close shaving;

3. Ifith'e tightening of the clamp be carried to the limit imposed bythe relations and dimensions of the clamp and holder, the position ofthe cutting edge and guard with relation to each other is changed insuch manner as to further increase the exposure of the cutting edge, andfurther decrease the ,protect'ion- ,of the guard, thus bringing thecutting edge into a position adapted for close shaving, without,however, causing sufficient exposure of the cutting edge to destroy theelement of safetyin use;

4. As further movement of the parts is impossible, it-is evident thatthe desired adjustments are-effected between two definitely fixedlimits, and that the razor is safe irrespectiveof the way in which itmay be adjusted by'the user. i

5. After tightening the clamp to the'limit,

that is, toithe close shaving position, any

change made by slackening the stress upon the clamp, decreases theexposure of the'cutting edge, increases the protection of the guard andincreases the factor of safety in use.

My invention thus provides a new method for adjusting safety razors inwhich increase in the clamping pressure decreases the factor of safetyupto the permissible exposure of mg pressure increases the factor ofsafety so that, as shown by the drawings, Figs. I

and III, the parts may be so proportioned Ill see

the cutting edge and decrease in the clampes es as to give no exposureof the cutting edge when the razor blade is in its initial position asclamped for use, and maximum exposure consistent with safety, when theclamp is tightened to the limit fixed by the construction andproportions of the parts.

I do not limit myself to the particular applications of my improvementwhich I have described in detail, nor to the use'of the two types ofappliances illustrated by the drawings, as my lnvention, as alreadyindicated, may be carried out by other means and may be applied to othertypes of holders and clamps than those shown and described. While Iprefer the types in which progressive tightening of the clamp changesthe adjustment from the least to the greatest exposure of the cuttingedges consistent with safety in use, my improvement may be applied totypes of holders and clamps pronate the distance by which the cuttingedge of the blade projects beyond a line drawn tangent to the outersurface of the clamp and also tangent to the outer surface of the guard,as indicated by the broken line e-d of Fig. I and ca5 of Fig. IV.

Having described my invention, 1 claim,

1. A safety razor including a holder hav ing a guard, a handle therefor,a clamp engaging said holder, a blade between clamp and holder, one ofsaid elements being flexible, means to flex said element, said blade, atthe initial position of flexure of the flexible element, having surfacecontact with said clamp, and a line contact with said holder.

2. A safety razor including a holder having a guard, a handle therefor,a clam engaging said holder, a blade between 0 amp and holder, ble,means to flex said element, said blade at the initial position offlexure of the flexi ble element, having surface contact with saidclamp, and two line contact with said holder. i

3. A safety razor including a holder having a guard, a handle therefor,a clamp engaging said holder, a blade between clam and holder, one ofsaid elements being flex1 ble, means to flex said element, said blade atthe initial position of flexure of the fiexi ble element, having surfacecontact with said clamp, and a line contact with said holder, said linecontact being between the longi tudinal center of said holder and theguard said surface contact including a portion of the blades uppersurface.

In witness whereof I have hereunto placed my hand this 16th day of July,1921.

HENRY MI. CHANGE. Witnesses CHAS. BUSH, CARL K. SOHULZE.

one of said elements being flexi-

